I am building a six XHP70 12v array flood light and am looking for some suggestions on the driver. The power source is 120vac. I want to build a PCB that holds the necessary components and also the LED’s mounted on copper sinkpads. 2400ma is maximum for each LED but the way I understand it 1050ma is where they were tested. I have a prototype light running now that is using a cheap 8amp CC driver. I can adjust the current and voltage with the meter to 1050ma@ 12vdc but when I hook up the led it only pulls a maximum of 750ma. I have the six running on 2 x 3 in parallel circuit now but regulation of current to each led is not possible. I have pictures of the system but have not figured out how to show them here.
So, armed with the data sheet above I’d also guess that you need to leave your current setting where it’s at and raise the voltage till you get to about 11.7volts measured across the LED while under load. I think you’re getting some voltage drop across your wires, or your power supply is allowing the voltage to sag under load.
I checked voltage voltage at the driver and it is 11.86. I did not check across the led’s because this is a temporary test setup. I am looking to build a PCB that is 3.5” round. It will have the six 20mm sinkpads and all the electronics mounted on it. The system also has a small cooling fan. The ultimate goal would be a self contained system you plug into 120vac. I need maximum efficiency and longevity as it will be under five year warranty. This is a commercial project so looking for someone that can design it for us. I will pay you for your services. I can give more info if your interested.
the plan is to mount the sink pads over a pcb? I hope that´s not enough, you need to let the heat leave the system, by using heat sinks- radiators or something similar. It will create a bit of heat
to post a picture, you need to upload it to a pic server, like tinypic.com, and then use the direct link provided by the server in the “insert picture” button, over the editor where you write.
Im curious to see the project
I agree - mounting the Sinkpads to the PCB will probably end in early death for the emitters. Maybe make the back plate of the light with cooling fins on the outside and pockets for positioning the Sinkpads on the inside. Cut holes through the PCB the same size and position as the Sinkpads. Then either the PCB or any of the Sinkpads can be installed/removed separately from the other(s). Order of operations for manufacturing can be more flexible then, and also troubleshooting if/when a problem is found by QC. Make sure the pockets are machined flat and smooth, and two screw holes are drilled and tapped for each Sinkpad, to ensure maximum heat transfer.
